Studies on growth and the nutritional, metabolic, and hormonal status of children with chronic renal failure on regular haemodialysis

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Abstract

The purpose of this study was to assess the nutritional, metabolic
and hormonal status of children with chronic renal failure, and to study
the pathogenesis of the growth retardation which is an important
clinical problem affecting these children. Sixteen children on
regular haemodialysis were observed over a period of one year. Growth was subnormal in most patients with delay in skeletal
maturation, and growth potential fell with advancing bone age. Body
weight was less affected than height presumably because all children
received energy supp1ementsin their diet. Puberty was delayed but
a
pubertal children grew better and had/more normal body cell mass than
prepubertal children. Significant increases were found in the fasting
levels of blood glucose, plasma insulin, growth hormone, glucagon,
Cortisol, luteinizing hormone, prolactin, triglycerides, cholesterol,
glycine and alanine, and significant decreases were observed in plasma
thyroxine, triiodothyronine, testosterone, branched-chain amino acids,
free fatty acids and glycerol. Growth velocity correlated positively
with plasma valine, leucine and gonadotrophin levels. In boys, growth
velocity correlated positively with plasma testosterone and inversely
with prolactin levels. Plasma triglyceride concentration was related
to both carbohydrate intake and plasma insulin level. There were
also positive correlations between growth hormone and fatty acids,
growth hormone and the branched-chain amino acids, serum somatomedin
and plasma transferrin, and between transferrin and the % deficit in
weight for height and for age. Extracellular water was increased
and intracellular water (cell mass) was decreased, but body fat was normal or increased in most patients. Glucose intolerance with
hyperinsulinaemia, non-suppressable hyperg1ucagonaemia and paradoxical
a
rises in plasma growth hormone levels after/glucose load were observed.
Fasting plasma alanine concentration correlated inversely with glucose
disappearance rate (Kg). The fall in plasma free fatty acids was more
marked than normal and was related to plasma insulin response. Basal
oxygen consumption was increased particularly in the more wasted
children. Manipulation of the diet for a further period of one year by
increasing the ratio of polyunsaturated to saturated fats lowered
plasma cholesterol level but not plasma triglycerides.
On the basis of the findings, it is suggested that the primary
defect is a peripheral resistance to insulin with respect to glucose
utilization accompanied by a decrease in the mobilization of endogenous
fat for energy production and a diversion of amino acids for energy
purposes with an increase in hepatic g1uconeogenesis and body protein
depletion. It was also suggested that energy and protein requirements
of uraemic children may be increased, and that energy supplements as
carbohydrate would increase body fat without affecting cell mass.
It is hoped that the information obtained from the study will
be helpful in further understanding the pathogenesis of growth retardation
in children with chronic renal failure and their nutritional needs,
and will provide guidelines for future research.